Transformer



R. L, BROWN TRANSFORMER Filed July 30, 1930 INVENToR Roy L. B rown.

' ATTORNEY Patented Nov. 17, 1931 UNITED STATES PATENT OFFICE BOY I.BBOW'N, Ol' SHARON, PENNSYLVANIA, ASSIGNOBv WESTINGHOUSE m0- &IANUI'ACTUBING COMPANY, A CORPORATION OFIPENNSYLVAINIA TMNSFORHEBApplication med July 30, 1930. Serial No. 471,685.

My invention relates to transformers and it has particular relation tothe provision of means for preventing noise and for supporting andbracing ransformer coils.

In transformers of he shell type, the coils or windings are oblong inshape and extend beyond the iron core at each end, thus leavin a spacebetween the end portions of the coils and' the iron.

When the windjn of a transformer are short-circuited or eavy overloadsoccur, severe mechanical stresses are set up within the transformerwhichtend to separate the coils in a direction normal to their faces and16 in a direction parallel to their faces. Ilo

prevent the movement of the coils in a direction normal to the faces,heavy plates are placed against the fiat faces of the end coils whichare bolted together. thereby tightly I clamping all the coils together.

It is also necessary to brace the coils against the stresses acting in aplane parallel to their faces and therefore tending to separate theprimary and second'ary coils in that direction.

To brace the coils against movement in a direction parallel to theirfaces and to clamp the transformer laminations tightly together,

it has heretofore been customary to insert T-beam tongue wedges, throughthe openings of the coils at the top and bottom, between'the iron andthe'end portions of the coils, and, in order to force these beams apartand to brace the coils, spreader bolts were applied between the beams.

While the tongue wedges have performed their function to a satisfactorydegree, it

y is the main object of this invention to provide a wedge that will moreeffectively brace the transformer coils against short-circuit stressesand to more tightly clamp together the transformer laminations, therebyreducing the noise when the transformer is energized. When a shortcircuit occurs within the transformer, the stresses set up in the wedgesare beam stresses which produce a shearing action that is veryundesirable.

Ono object of my invention is to provide means for effectively bracingthe coils of a transformer against movement caused by short-circuitstresses.

Another object of my invention is to provide means for clampingtransformer laminations to ther and for so bracing the coils of a transormer that noise will be prevented when the transformer is energized.

Another object of my invention is to provide liifieans for bracing thetransformer coils in which the stresses set up in the bracing means, durmg short-circuit conditions, are compression stresses.

My invention will be better understood by referring to the followingdescription, when read in conJunction with the accompanying drawings inwhich,

Figure 1 is a view, in .front elevation, of a transformer provided withthe means for clamping the laminations together and bracing the coilsutilized in the practice of my invention.

Fig. 2 is a sectional view, taken on the line II-II of Fig. 1.

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Fig. 3 is a side elevational view of a cooperating pair of triangularwedges em ployed in the practice of my invention.

Fig. 4 is an end elevational view of wedges shown in Fig. 3. l

Fig. 5 is a perspective view of a wedge employed in the practice of myinvention.

Fig. 6 is a detail view illustrating the manner in which the triangularwedges may be removed from the transformer.

Referring to the drawings, a shell-type transformer is illustratedcomprising core members 2, consisting of a plurality of laminations 3and cooperating primary and sccondary windings 4 and 6, inductivelyrelated thereto. The laminations 3 are supported and bound together byupper and lower longitudinally and laterally extending channel members,or end frames, 8 and 10, respectively, connected together by a'pluralityof vertically extending tie bolts 12.` The 9|; I

channel members 10 have apertures 13 therein for a purpose to behereafter described.

The coils are prevented from moving in a direction normal to their facesby pressure plates 14 and spacing blocks 16 that are connected togetherby longitudinally extending bolts 18.

To aid in filling the space between the lower edges of the laminationsand the end portions of the coils, and to assist in supporting the ironof the core members, a wedge 22 is inserted therein. The wedge 22 ispreferably of T-shape in cross section, having a horizontal portion 24and a vertical web portion 26, but/it may be constructed of a horizontalplate and a separate andy abutting vertical web member. The wedge 22 isdisposed with the horizontal portion 24 in engagement with the bottomsof-the laminations and with the vertical web member 26 extending betweenthe core members.

The coils are supported and vertical movement thereof is prevented andthe transformer laminations are tightly clamped together by an upperlongitudinally extending tongue wedge 28. Longitudinally extendingspacing members 29 are disposed between the lower wedge 22 and the lowerend portions of the coils and also between .the upper wedge 28 and theupper end portions of the coils to further assist in supporting andinsulating the coils.

The wedge 28 comprises two cooperating members 32 and 34 of triangularshape, each having outside walls 36, an end wall 38, having upper andlower openings 39 therein, and

a center wall 40 extending along the longitudinal axis of each memberand parallel to the side walls 36. Web members 42 extend between theside walls 36 and the center wall `40 and have threaded openings 44therein,

one opening being disposed between each side wall and the center wall.rlhe longitudinally extending walls of the wedge members 32 and 34 arerespectively provided with cooperating tongues 45 and grooves 46 inorder that the members may easily slide on each other and form a tightjoint. Apertures or openings 47 are provided in the bases of the wedgemembers 32 and 34 to permit circulation of the transformer coolin oil.

o place the wedge 28 in position, the ends of the wedge member 34 aresupported by the upper channel member 10, and extend through theopenings 13, and the wedge member 36 is disposed in cooperating relationthereto. Bolts 48 extend through the upper openings in the end walls 38of each of the members 32 and 34 and through the web members 42 of theother wedge member.

When the bolts are tightened, the two wedge members 32 and 34 are drawntogether and are tightly clamped, after which the bolts may be removed.During shipment of the transformer, the wedge members may become loose,due to vibration or other causes, and, to prevent this, they may bebolted together by bolts 50.

In order not to provide a path of low magnetic reluctance for the straymagnetic flux, thereby producing excessive heat that would injure ordestroy the coil insulation, the upper and lower tongue wedges areconstructed of non-magnetic'material.

Should a short circuit or a fault occur within the transformer, thestresses set up that are normal to the face of the coils are taken up bythe end plates 14, and the stresses that are parallel to the faces ofthe coil are taken up by the wedge member 28. The stresses on the wedgemember 28 are compresslon stresses and there is no shearing aetionbetween the coils.

When it is necessary to remove the wedge members 32 and 34, a channelmember 54 is placed against the upper channel member 10, and the bolts48 extend through the lower openmgs in the end wall 38 and the webmember 42 of the member 32. When the bolt is tightened, the member 32 ispulled away from the member 34, thereby loosening the Joint andpermitting the wedge members 32 and 34 to be easily removed.

Some of the advantages to be derived from this construction of the upperwedge are, the members 32 and 34 are light, well ventilated and areclamped tightly together by the wedging action of the members, therebytightly clamping the transformer iron and' coils and thus reducing thenoise when the transformer is energized; the cost of the transformer maybe reduced, as it is only necessary to machine the surfaces of the wedgemembers that are in the contact, and' the size of the openings 47 may bereduced to that required for ventilation only.

Since 'many modifications may be. made in the features of my inventionwithout departing from the spirit thereof, I do not Wish to be limitedotherwise than by the scope of the appended claims. v

I claim as my invention:

l. In a transformer, a core member comprising a stack of laminations ofmagnetic material, and a plurality of substantially flat windingsinductively related thereto, means for preventing movement of saidwindings in a direction normal to their faces, and means for prevent-ingmovement of the' windings in a direction parallel to their faces and'forcompressing the laminations comprismg two cooperating members disposedbetween the laminations and the end of the windings, said members havingengaging.

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nations comprising two cooperating triangueecting a relative movement ofsaid wedges s lar shaped members disposed between onei,

end of the laminations and the windings and o adapted to move over eachother, and means for moving the triangular members over each other to`wedge them tightly in said position. 3. A transformer comprising aplurality ofcore members, each consistm of a Vplu- 'rality oflaminationsof magnetic material,

and substantially ilat cooperating primary Y and secondary windingslinking said core members, means for preventin movement of for varyingthe pressure between said coils and said core structure. v

In testimony whereof, I have hereunto f July, 1930. BROWN;

scribed 'my'name this 17th dei ROY the 4laminations and. 'preventingmovement of said .windings -in `a direction' parallel to their facescomprising two trian ar shaped members having their hypotenuse inengagement and dis sed 4between the laminations' A andthe win ings, andmeans-for effecting relative movement, of said trian ular members to tihtlywedge them in sai position. ,v 4. A. s ell-typetransformercomprisingla plurality o f core members, each comprism astack lof laminations'of magnetic mteria cooperatinlg Erimary landsecondaryv 'oblong rected wedges positioned witli'n t windings fortightly compressing eachstack of lami ingsaid -core,members, means.

nations and for preventing movement Aof said windings in a direction11ormalto the laminations comprising two wedge-shape members en agingeach other and between the aminations and the end portions ofthewindings, ,and means for tightening the wedge-shape members in saidposition.

5. A shell-type transformer comprising a plurality of core members, eachcomprising a stack of laminations of m etic materia and cooperatingprimary an secondary oblong windings linkin said core members, means forclamping t e laminationstightly together and for preventing movement ofsaid windings comprising apair of aper- Atured wedge-shape members 1n`engagement with each other and disposed between the core members andthe end portions of the v windings, and means for' tightening the wedgelmembers in said position comprising bolts extending from one wedgemember to the other wedge member and apted to pull said wedge memberstogether.

6. In electrical apparatus, a core structure comprising a plura it Voflaminations of magnetic material, a plurality of coils-poispos'edsitioned about a portion of said core structure, means for clampingsaidlaminations together comprising a pair of opgositely dijacent to saidlaminations.

7. In' lectrical apparatus, a core structure comprising a plurality oflaminations of magnetic material, a plurality of coils positioned abouta portion of said core struc ture, means for clampin said laminationsvtogether comprising a pair of oppositely directed wedges positionedwithin the coils adjacent to said 1aminatons,=and means for coils ad.

